396 research outputs found
Molecular characterisation, evolution and expression analysis of g-type lysozymes in Ciona intestinalis
Lysozyme is an important defense molecule of the innate immune system. Known for its bactericidal
properties, lysozyme catalyzes the hydrolysis of b-(1,4)-glycosidic bonds between the N-acetyl glucosamine
and N-acetyl muramic acid in the peptidoglycan layer of bacterial cell walls. In this study, the
complete coding sequence of four g-type lysozymes were identified in Ciona intestinalis. Phylogenetic
analysis and modelling supported the hypothesis of a close relationship with the vertebrate g-type lysozymes
suggesting that the C. intestinalis g-type lysozyme genes (CiLys-g1, Cilys-g2, CiLys-g3, CiLys-g4)
share a common ancestor in the chordate lineage. Protein motif searches indicated that C. intestinalis gtype
lysozymes contain a GEWL domain with a GXXQ signature, typical of goose lysozymes. Quantitative
Real-Time PCR analysis results showed that transcripts are expressed in various tissues from
C. intestinalis. In order to determine the involvement of C. intestinalis g-type lysozymes in immunity, their
expression was analyzed in the pharynx, showing that transcripts were significantly up-regulated in
response to a challenge with lipopolysaccharide (LPS). These data support the view that CiLys g-type are
molecules with potential for immune defense system against bacterial infection
A new Leucoagaricus species of section Piloselli (Agaricales, Agaricaceae) from Spain
The new species Leucoagaricus variicolor is described from a public park in Zaragoza, Spain, based on both morphological and molecular characters. Illustrations of fresh basidiomata in situ and of the main macro- and micromorphological features are added. Leucoagaricus variicolor belongs to section Piloselli and is compared with similar taxa
In the ovary of Ciona intestinalis (Type A), immune-related galectin and phenoloxidase genes are differentially expressed by the follicle accessory cells
Riboprobes (in situ hybridization) and antibodies (immunohistochemistry), previously used to show the upregulation of Ciona intestinalis (Type A) galectins (CiLgals-a, CiLgals-b) and phenoloxidase (CinPO2) immune-related genes, were tested on histological sections of the ovary. The ovarian follicles are composed of oocytes encased by follicular cells (FCs) and test cells (TCs). Results show the transcription upregulation of both CiLgals and CinPO2 genes in the vitellogenic FCs, conversely distinct cytolocalization of the proteins are shown. At vitellogenic stage, the CiLgals are localized in the FCs, in the oocyte cytoplasm, and close to the germinal vesicle (GV), whereas the CinPO2 was never identified in the FCs. In a presumptive advanced phase and at the post-vitellogenic stage the TCs appear to be labelled by the CinPO2 riboprobe, and the protein identified by the antibody suggesting an mRNA transcytosis process from FCs. At post-vitellogenic stage the CiLgals mainly enrich the GV nucleoplasm, whereas the CinPO2 is contained in TCs and in the ooplasm but never found in the GV. This finding sheds new light on a former paper in which TCs were reported to be the only CinPO2-producing cells in the ovarian follicle. Finally, CiLgals and CinPO2 genes transcription and proteins production seem to be associated with accessory cells during their differentiation from vitellogenic to post-vitellogenic stage. The present findings promote further research on the early upregulation of immune-related genes, and the potential multifunctional role of the produced proteins. In addition further insight on the accessory cells involvement in ascidian oogenesis are reported
Ciona intestinalis galectin (CiLgals-a and CiLgals-b) genes are differentially expressed in endostyle zones and challenged by LPS
Immunohistochemical and in situ hybridization assays were performed to answer the question whether
the endostyle, that is the initial gastro-intestinal trait of Ciona intestinalis pharynx, is involved in galectin
(CiLgals-a and CiLgals-b) production during the pharynx inflammatory response to LPS inoculation.
Specific anti-CiLgal-a and anti-CiLgals-b antibodies, and oligonucleotide probes, that mark inflammatory
hemocytes inside the pharynx vessels and vessel epithelium as shown by a previous paper, were assayed
on endostyle histological sections. For the first time, we show that galectins are produced by endostyle
zones, and both CiLgals-a and eb genes are upregulated by LPS. CiLgals-a and CiLgals-b are constitutively
expressed in the endostyle zone 2 and 3, respectively, both genes are upregulated by LPS in the zone 2,
and CiLgals-b in the zone 3 and 4. The antibody-reacting material contained in intracellular and extracellular
large vesicles suggest an unexpected vesicle-dependent transporting mechanism of galectins not
provided with signal peptide. Differential expression and gene upregulation in not-treated and LPStreated
specimens, support the role of endostyle galectins both in filter feeding and defense responses
Differential expression of two glucocorticoid receptors in seabass (teleost fish) head kidney after exogeneous cortisol inoculation
Stressful conditions include a prompt release of corticosteroid hormones which can mediate gene expression through glucocorticoid receptors (GR). Since two seabass (Dicentrarchus labrax) GRs have been cloned and sequenced from peritoneal cavity cells (DlGR1) and liver (DlGR2), a comparative amino acid sequence analysis that included Haplochromis burtoni HbGRs, was carried out and homologies disclosed. The DlGR1 and DlGR2 deduced aminoacid sequences showed 61% identity (I) and 70% similarity (S). Moreover, DlGR2 was similar to HbGR2b (69% I, 73% S), and the DlGR1 to HbGR1 (72% I, 78% S). In addition, we examined the expression of the DlGRs after exogeneous cortisol inoculation into the peritoneal cavity, mimicking stress
effects. At various times after the administration (3 h, 24 h, 1 week), gene expressions was evaluated in head
kidney by real-time PCR. In addition, immunoblotting and densitometry analyses were performed with anti- DlGR1 antibodies. Although sea bass head kidney expressed both DlGR1 and DlGR2 they were differentially modulated by intraperitoneal implant of exogeneous cortisol
Isolation of a novel LPS-induced component of the ML superfamily in Ciona intestinalis
ML superfamily represents a group of proteins playing important roles in lipid metabolism and innate
immune response. In this study, we report the identification of the first component of the ML superfamily
in the invertebrate Ciona intestinalis by means of a subtractive hybridization strategy. Sequence
homology and phylogenetic analysis showed that this protein forms a specific clade with vertebrate
components of the Niemann-Pick type C2 protein and, for this reason, it has been named Ci-NPC2. The
putative Ci-NPC2 is a 150 amino acids long protein with a short signal peptide, seven cysteine residues,
three putative lipid binding site and a three-dimensional model showing a characteristic b-strand
structure. Gene expression analysis demonstrated that the Ci-NPC2 protein is positively upregulated after
LPS inoculum with a peak of expression 1 h after challenge. Finally, in-situ hybridization demonstrated
that the Ci-NPC2 protein is preferentially expressed in hemocytes inside the vessel lumen
A serum fucose-binding lectin (D1FBL) from adult Didentrarchus labrax is expressed in larva and juvenile tissue and contained in eggs
The purification, cloning, sequencing, molecular
properties and expression of a fucose-binding lectin from
the serum of Dicentrarchus labrax (DlFBL) have been
previously reported. We now describe the distribution and
expression of DlFBL during fish ontogeny. Immunohistochemistry
and in situ hybridization assays were carried out
at various developmental stages (from 10 days posthatching
larvae to juveniles). Another fucose-binding
lectin, similar to DlFBL in biochemical, immunochemical
and agglutinating properties, was extracted and purified
from eggs and appeared to be localized in the embryo yolk
sack residual. DlFBL was found in columnar and goblet
cells of the intestinal epithelium of larvae (from 20 days
post-hatching) and juveniles and in parenchymal tissue of
juveniles. DlFBL mRNA and protein were detected in the
intestinal epithelium and in hepatocytes. An amplification
product from degenerate primers indicates that lectin
isotypes with DlFBL epitopes are expressed in eggs and
embryos. Whether the lectin fraction isolated from eggs and
embryos includes DlFBL of maternal origin remains
unclear
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